It looks like a light ballast. On Boeings, they typically have brass colored casing and are about 6x2x3 inches, have schematics on the side, and of course have the ID sticker on the top. The only other parts I can think of that are similar in size is cargo smoke detectors, other that I'm drawing a blank.

We can ask if AMTMAN could look up P/N MOD55(S?)37 and S/N 144B(8?) and see what he can find.

ETA: Seat electronic boxes are about the same size and appearance too, but they usually have lots of cooling holes in the case.
ETA2:.....or maybe they don't!

Very close. The part in question is the power supply for the emergency lights. I'm suprised no one sent me a IM about this. JamesB sent me an e-mail about it it but it was not directly related to JREF.

__________________You of course would forget that the original burden of proof falls upon truthers. Swing Dangler commenting on the air phones issue

Here is a diagram of a Boeing 767. I see numerous potential exit points. For example, the Nose Gear Door.... A-Train on "potential" exits on a 767.